Gardaí have warned convicted drug dealer John Gilligan that his life is in immediate danger after what they believe was a failed attempt to shoot him dead when gunmen went to the wrong pub.

A senior Garda officer said providing him with an armed escort to prevent any future attempt on his life did not arise.

While the Garda at times provided protection to people under threat from gangs, such as witnesses in court cases or journalists, it did not offer that service to convicted criminals.

Dubliner Gilligan (61) was drinking in the Hole in the Wall pub on Blackhorse Avenue beside Dublin’s Phoenix Park on Thursday afternoon when two armed men arrived at the Halfway House in Ashtown less than 1km away.

After they were unable to find him they left on a motorbike. They were chased by gardaí and threw their gun away. It has since been recovered.

Garda sources said they were treating the incident as an attempt to murder the gang leader, adding that, aside from the information on Mr Gilligan’s whereabouts being wrong, the planning was elaborate.

“You’re talking about robbing a bike, sourcing a gun and getting the money to pay two guys willing to do it. A lot of work went into that,” said one source.

Other sources said it was unclear if the motive behind the botched attack was related to a dispute Mr Gilligan had while in Portlaoise Prison or whether he had crossed rival drug dealers since his release in mid-October after 17 years in jail.

CustomersGardaí were alerted to Thursday’s incident when both customers and staff in the Halfway House rang 999 to report that a man wearing a black motorcycle helmet had walked into the pub with a handgun just before 4pm. He shouted “where’s Gilligan”, before being challenged by a staff member and fleeing on realising his intended victim was not in the pub.

The armed man got back on a waiting motorbike outside driven by an accomplice, and as they drove away they were seen by unarmed gardai in a patrol car who had sped to the scene.

They chased the two men on the motorbike down River Road towards Finglas, and at Ratoath Road in the north Dublin suburb they failed to bring the bike to a stop.

A 9mm Luger pistol was thrown or fell from the motorbike, and the two men subsequently managed to escape.

The gun was found and has since been taken for ballistic and forensic analysis.

Mr Gilligan was in the High Court in Dublin yesterday for a hearing related to the seizure of land and houses the Criminal Assets Bureau claims are the proceeds of his crimes.

Gardaí approached him in the precincts of the courts and formally warned him his life was in danger, as they are legally obliged to do in such circumstances.